The design of the character (Koriand'r) incorporated aspects of many existing characters, artist George Pérez talking about the creation of the character noted that

Koriand'r, Starfire's real name, is a princess of the fictional planet Tamaran in the Vega system, and was in line to rule the planet as Queen. Komand'r ("commander", also known as Blackfire), her older sister, developed a bitter rivalry with her after suffering a disease in infancy that robbed her of the ability to harness solar energy to allow her to fly, and by extension, her right to the throne. This rivalry continued and intensified when the siblings were sent for warrior training with the Warlords of Okaara. Things came to a head during a sparring exercise in which Komand'r attempted to kill her sister. As a result, Komand'r was expelled and she swore vengeance.

That revenge came in a plot where Komand'r betrayed her planet by supplying detailed information about Tamaran's defenses to their enemies, the Citadel. They conquered Tamaran with ease, and the surrender conditions included the enslavement of Koriand'r, who was never permitted to return, since that would mean the Citadel would devastate the planet for abrogating the treaty. To Kory's horror, she learned that Komand'r was her master; Koriand'r's older sister made the most of her sibling's bondage with years of horrific servitude, torture and unprevented sexual exploitation at the hands of others. When Koriand'r killed one of her captors who had previously raped her, Komand'r decided to execute her as punishment, but the sisters were attacked and captured by the Psions. Psions, a group of sadistic alien scientists, performed a deadly experiment on both sisters to see how much energy their Tamaranean bodies could absorb before exploding from the overload. During the procedure, Komand'r's forces attacked the Psion ship to retrieve her. While the Psions were distracted, Kory broke free using her starbolts - destructive blasts of solar energy - which were a result of the experimentation. Against her better judgment, she decided to free Komand'r, who was still absorbing energy. However, far from grateful, Komand'r struck her sister down with the same, but more intense, power, and had her restrained for later execution.